Compounding things, for individuals with Arabic names, sanctions lists provide only a few alternate spellings. The U.S. Treasury Department offers 12 possible spellings for Moammar Gadhafi, though language experts say there are more than 100 for the family name alone.

Unlike other so-called script languages such as Chinese or Japanese, Arabic has no transliteration standards. Pronunciation of the same names varies by place, and written Arabic contains few vowels, opening the door to a larger range of acceptable translations. Mohamed can also be transliterated as Mahmut, Mehmud or dozens of other variants.

Banks allow clients to transliterate their names as they see fit when they open new accounts. When a government publishes a new watch list, the banks' software uses so-called fuzzy logic to search for alternative spellings, similar to how Google suggests alternative phrases when it detects a possible typo in a search.

Of course, all that assumes that they're opening accounts under their own names anyway... I would assume that many have hidden accounts under corporation names or front men or simply fictitious individuals, and you would think that those would be more significant... and much harder to track down.